Mortar pumps with eccentric screws are known from the prior art. In some cases, they are designed as submersible pumps which project into a storage vessel by way of a suction end, suck the delivery material out of this storage vessel and deliver it, via a discharge line, to the processing location, in particular to mortar-spray equipment. Also known are horizontal mortar pumps which use an eccentric screw to remove mortar out of a storage vessel via a suction-intake region and transport the same into a pressure region for processing under pressure.
The cleaning of the eccentric screw pump is problematic in the case of the known apparatuses according to the prior art. It is necessary here for the rotor, which constitutes the screw, to be separated from the stator, in which the screw runs. However, since the pump action results from elastically sealing deformation of the stator as the screw rotates through the same, this stator provides a considerable level of resistance, during dismantling, through the screw simply being pulled out. The prior art, for example, DE 103 37 382 A1, discloses means which overcome this resistance. However, these means are expensive and have to be arranged separately, using additional operating steps, on the apparatus which is to be cleaned.